#define ToBE32(x) \
    ((uint32_t)((((uint32_t)(x) & 0xff000000) >> 24) | \
	        (((uint32_t)(x) & 0x00ff0000) >>  8) | \
	        (((uint32_t)(x) & 0x0000ff00) <<  8) | \
	        (((uint32_t)(x) & 0x000000ff) << 24)))

#define ToBE64(x) \
    ((uint64_t)((((uint64_t)(x) & 0xff00000000000000ULL) >> 56) | \
	        (((uint64_t)(x) & 0x00ff000000000000ULL) >> 40) | \
	        (((uint64_t)(x) & 0x0000ff0000000000ULL) >> 24) | \
	        (((uint64_t)(x) & 0x000000ff00000000ULL) >>  8) | \
	        (((uint64_t)(x) & 0x00000000ff000000ULL) <<  8) | \
	        (((uint64_t)(x) & 0x0000000000ff0000ULL) << 24) | \
	        (((uint64_t)(x) & 0x000000000000ff00ULL) << 40) | \
	        (((uint64_t)(x) & 0x00000000000000ffULL) << 56)))

#define IN_DATA_SIZE 128
#define OUT_DATA_SIZE 32
#define NONCE_OFFSET 76

typedef unsigned int uint32_t;
typedef unsigned long long uint64_t;
typedef unsigned char uint8_t;

inline void WriteBE32_EX(unsigned char* ptr, uint32_t x) {
    uint32_t v = ToBE32(x);
    memcpy(ptr, (char*)&v, 4);
}

inline void WriteBE64_EX(unsigned char* ptr, uint64_t x) {
    uint64_t v = ToBE64(x);
    memcpy(ptr, (char*)&v, 8);
}

inline uint32_t ReadBE32_EX(const unsigned char* ptr) {
    uint32_t x;
    memcpy((char*)&x, ptr, 4);
    // return be32toh(x);
    return ToBE32(x);
}

inline uint32_t Ch(uint32_t x, uint32_t y, uint32_t z) { return z ^ (x & (y ^ z)); }
inline uint32_t Maj(uint32_t x, uint32_t y, uint32_t z) { return (x & y) | (z & (x | y)); }
inline uint32_t Sigma0(uint32_t x) { return (x >> 2 | x << 30) ^ (x >> 13 | x << 19) ^ (x >> 22 | x << 10); }
inline uint32_t Sigma1(uint32_t x) { return (x >> 6 | x << 26) ^ (x >> 11 | x << 21) ^ (x >> 25 | x << 7); }
inline uint32_t sigma0(uint32_t x) { return (x >> 7 | x << 25) ^ (x >> 18 | x << 14) ^ (x >> 3); }
inline uint32_t sigma1(uint32_t x) { return (x >> 17 | x << 15) ^ (x >> 19 | x << 13) ^ (x >> 10); }

inline void Round(
        uint32_t a,
        uint32_t b,
        uint32_t c,
        uint32_t* d,
        uint32_t e,
        uint32_t f,
        uint32_t g,
        uint32_t* h,
        uint32_t k,
        uint32_t w) {

    uint32_t t1 = *h + Sigma1(e) + Ch(e, f, g) + k + w;
    uint32_t t2 = Sigma0(a) + Maj(a, b, c);
    *d += t1;
    *h = t1 + t2;
}

inline void T(uint32_t* s, const uint8_t* chunk, size_t blocks) {
    #pragma unroll
    while(blocks--) {
        uint32_t a = s[0], b = s[1], c = s[2], d = s[3], e = s[4], f = s[5], g = s[6], h = s[7];
        uint32_t w0, w1, w2, w3, w4, w5, w6, w7, w8, w9, w10, w11, w12, w13, w14, w15;

        Round(a, b, c, &d, e, f, g, &h, 0x428a2f98, w0 = ReadBE32_EX(chunk + 0));
        Round(h, a, b, &c, d, e, f, &g, 0x71374491, w1 = ReadBE32_EX(chunk + 4));
        Round(g, h, a, &b, c, d, e, &f, 0xb5c0fbcf, w2 = ReadBE32_EX(chunk + 8));
        Round(f, g, h, &a, b, c, d, &e, 0xe9b5dba5, w3 = ReadBE32_EX(chunk + 12));
        Round(e, f, g, &h, a, b, c, &d, 0x3956c25b, w4 = ReadBE32_EX(chunk + 16));
        Round(d, e, f, &g, h, a, b, &c, 0x59f111f1, w5 = ReadBE32_EX(chunk + 20));
        Round(c, d, e, &f, g, h, a, &b, 0x923f82a4, w6 = ReadBE32_EX(chunk + 24));
        Round(b, c, d, &e, f, g, h, &a, 0xab1c5ed5, w7 = ReadBE32_EX(chunk + 28));
        Round(a, b, c, &d, e, f, g, &h, 0xd807aa98, w8 = ReadBE32_EX(chunk + 32));
        Round(h, a, b, &c, d, e, f, &g, 0x12835b01, w9 = ReadBE32_EX(chunk + 36));
        Round(g, h, a, &b, c, d, e, &f, 0x243185be, w10 = ReadBE32_EX(chunk + 40));
        Round(f, g, h, &a, b, c, d, &e, 0x550c7dc3, w11 = ReadBE32_EX(chunk + 44));
        Round(e, f, g, &h, a, b, c, &d, 0x72be5d74, w12 = ReadBE32_EX(chunk + 48));
        Round(d, e, f, &g, h, a, b, &c, 0x80deb1fe, w13 = ReadBE32_EX(chunk + 52));
        Round(c, d, e, &f, g, h, a, &b, 0x9bdc06a7, w14 = ReadBE32_EX(chunk + 56));
        Round(b, c, d, &e, f, g, h, &a, 0xc19bf174, w15 = ReadBE32_EX(chunk + 60));

        Round(a, b, c, &d, e, f, g, &h, 0xe49b69c1, w0 += sigma1(w14) + w9 + sigma0(w1));
        Round(h, a, b, &c, d, e, f, &g, 0xefbe4786, w1 += sigma1(w15) + w10 + sigma0(w2));
        Round(g, h, a, &b, c, d, e, &f, 0x0fc19dc6, w2 += sigma1(w0) + w11 + sigma0(w3));
        Round(f, g, h, &a, b, c, d, &e, 0x240ca1cc, w3 += sigma1(w1) + w12 + sigma0(w4));
        Round(e, f, g, &h, a, b, c, &d, 0x2de92c6f, w4 += sigma1(w2) + w13 + sigma0(w5));
        Round(d, e, f, &g, h, a, b, &c, 0x4a7484aa, w5 += sigma1(w3) + w14 + sigma0(w6));
        Round(c, d, e, &f, g, h, a, &b, 0x5cb0a9dc, w6 += sigma1(w4) + w15 + sigma0(w7));
        Round(b, c, d, &e, f, g, h, &a, 0x76f988da, w7 += sigma1(w5) + w0 + sigma0(w8));
        Round(a, b, c, &d, e, f, g, &h, 0x983e5152, w8 += sigma1(w6) + w1 + sigma0(w9));
        Round(h, a, b, &c, d, e, f, &g, 0xa831c66d, w9 += sigma1(w7) + w2 + sigma0(w10));
        Round(g, h, a, &b, c, d, e, &f, 0xb00327c8, w10 += sigma1(w8) + w3 + sigma0(w11));
        Round(f, g, h, &a, b, c, d, &e, 0xbf597fc7, w11 += sigma1(w9) + w4 + sigma0(w12));
        Round(e, f, g, &h, a, b, c, &d, 0xc6e00bf3, w12 += sigma1(w10) + w5 + sigma0(w13));
        Round(d, e, f, &g, h, a, b, &c, 0xd5a79147, w13 += sigma1(w11) + w6 + sigma0(w14));
        Round(c, d, e, &f, g, h, a, &b, 0x06ca6351, w14 += sigma1(w12) + w7 + sigma0(w15));
        Round(b, c, d, &e, f, g, h, &a, 0x14292967, w15 += sigma1(w13) + w8 + sigma0(w0));

        Round(a, b, c, &d, e, f, g, &h, 0x27b70a85, w0 += sigma1(w14) + w9 + sigma0(w1));
        Round(h, a, b, &c, d, e, f, &g, 0x2e1b2138, w1 += sigma1(w15) + w10 + sigma0(w2));
        Round(g, h, a, &b, c, d, e, &f, 0x4d2c6dfc, w2 += sigma1(w0) + w11 + sigma0(w3));
        Round(f, g, h, &a, b, c, d, &e, 0x53380d13, w3 += sigma1(w1) + w12 + sigma0(w4));
        Round(e, f, g, &h, a, b, c, &d, 0x650a7354, w4 += sigma1(w2) + w13 + sigma0(w5));
        Round(d, e, f, &g, h, a, b, &c, 0x766a0abb, w5 += sigma1(w3) + w14 + sigma0(w6));
        Round(c, d, e, &f, g, h, a, &b, 0x81c2c92e, w6 += sigma1(w4) + w15 + sigma0(w7));
        Round(b, c, d, &e, f, g, h, &a, 0x92722c85, w7 += sigma1(w5) + w0 + sigma0(w8));
        Round(a, b, c, &d, e, f, g, &h, 0xa2bfe8a1, w8 += sigma1(w6) + w1 + sigma0(w9));
        Round(h, a, b, &c, d, e, f, &g, 0xa81a664b, w9 += sigma1(w7) + w2 + sigma0(w10));
        Round(g, h, a, &b, c, d, e, &f, 0xc24b8b70, w10 += sigma1(w8) + w3 + sigma0(w11));
        Round(f, g, h, &a, b, c, d, &e, 0xc76c51a3, w11 += sigma1(w9) + w4 + sigma0(w12));
        Round(e, f, g, &h, a, b, c, &d, 0xd192e819, w12 += sigma1(w10) + w5 + sigma0(w13));
        Round(d, e, f, &g, h, a, b, &c, 0xd6990624, w13 += sigma1(w11) + w6 + sigma0(w14));
        Round(c, d, e, &f, g, h, a, &b, 0xf40e3585, w14 += sigma1(w12) + w7 + sigma0(w15));
        Round(b, c, d, &e, f, g, h, &a, 0x106aa070, w15 += sigma1(w13) + w8 + sigma0(w0));

        Round(a, b, c, &d, e, f, g, &h, 0x19a4c116, w0 += sigma1(w14) + w9 + sigma0(w1));
        Round(h, a, b, &c, d, e, f, &g, 0x1e376c08, w1 += sigma1(w15) + w10 + sigma0(w2));
        Round(g, h, a, &b, c, d, e, &f, 0x2748774c, w2 += sigma1(w0) + w11 + sigma0(w3));
        Round(f, g, h, &a, b, c, d, &e, 0x34b0bcb5, w3 += sigma1(w1) + w12 + sigma0(w4));
        Round(e, f, g, &h, a, b, c, &d, 0x391c0cb3, w4 += sigma1(w2) + w13 + sigma0(w5));
        Round(d, e, f, &g, h, a, b, &c, 0x4ed8aa4a, w5 += sigma1(w3) + w14 + sigma0(w6));
        Round(c, d, e, &f, g, h, a, &b, 0x5b9cca4f, w6 += sigma1(w4) + w15 + sigma0(w7));
        Round(b, c, d, &e, f, g, h, &a, 0x682e6ff3, w7 += sigma1(w5) + w0 + sigma0(w8));
        Round(a, b, c, &d, e, f, g, &h, 0x748f82ee, w8 += sigma1(w6) + w1 + sigma0(w9));
        Round(h, a, b, &c, d, e, f, &g, 0x78a5636f, w9 += sigma1(w7) + w2 + sigma0(w10));
        Round(g, h, a, &b, c, d, e, &f, 0x84c87814, w10 += sigma1(w8) + w3 + sigma0(w11));
        Round(f, g, h, &a, b, c, d, &e, 0x8cc70208, w11 += sigma1(w9) + w4 + sigma0(w12));
        Round(e, f, g, &h, a, b, c, &d, 0x90befffa, w12 += sigma1(w10) + w5 + sigma0(w13));
        Round(d, e, f, &g, h, a, b, &c, 0xa4506ceb, w13 += sigma1(w11) + w6 + sigma0(w14));
        Round(c, d, e, &f, g, h, a, &b, 0xbef9a3f7, w14 + sigma1(w12) + w7 + sigma0(w15));
        Round(b, c, d, &e, f, g, h, &a, 0xc67178f2, w15 + sigma1(w13) + w8 + sigma0(w0));

        s[0] += a;
        s[1] += b;
        s[2] += c;
        s[3] += d;
        s[4] += e;
        s[5] += f;
        s[6] += g;
        s[7] += h;
        chunk += 64;
    }
}

inline void Reset(uint32_t* s) {
    // _sha256 初始hash
    s[0] = 0x6a09e667ul;
    s[1] = 0xbb67ae85ul;
    s[2] = 0x3c6ef372ul;
    s[3] = 0xa54ff53aul;
    s[4] = 0x510e527ful;
    s[5] = 0x9b05688cul;
    s[6] = 0x1f83d9abul;
    s[7] = 0x5be0cd19ul;
}

inline void Finalize(uint32_t* s, uint8_t* out) {
    WriteBE32_EX(out, s[0]);
    WriteBE32_EX(out + 4, s[1]);
    WriteBE32_EX(out + 8, s[2]);
    WriteBE32_EX(out + 12, s[3]);
    WriteBE32_EX(out + 16, s[4]);
    WriteBE32_EX(out + 20, s[5]);
    WriteBE32_EX(out + 24, s[6]);
    WriteBE32_EX(out + 28, s[7]);
}

inline void DoHash(uint32_t* s, uint8_t* data, uint8_t blocks, uint8_t* out) {
    Reset(s);
    T(s, data, blocks);
    Finalize(s, out);
}


/**
 *
 * @param pIn 根据sha256补位规则好的block头信息数组
 * @param pOut 双sha256后的hash结果数组
 * @param nonceOffset  nonce的起始点
 */
__kernel void BtcDoubleSHA256(__global uint8_t* pIn, __global uint8_t* pOut, unsigned int nonceOffset) {
    /**
     * 双Sha256 Hash
     * 1. pIn内是已经按照sha256规则补位好的128byte的区块头数据
     *      128byte=1024bit=区块头(80byte=640bit)+补位(384bit=48byte)
     * 2. 修改pIn内区块头内的nonce数据
     * 3. 对修改后的pIn做一次sha256 hash运算
     * 4. 对上述运算后的32byte的hash结果按sha256规则再次进行补位到512bit(64byte)
     * 5. 再次对补位后的64byte做第二次sha256 hash运算
     * 6. 将第二次hash结果输出
     */

    uint32_t    _s[8]; // sha256初始因子
    uint8_t     hashResult[64];

    // 当前 puid
    int puId = get_global_id(0);

    // 当前需要处理的数据从global拷贝到private内存中
    //  1. 不能直接使用global参数调用其它非global参数的函数
    //  2. private内存的读写速度优于global
    uint8_t data[IN_DATA_SIZE];
    #pragma unroll
    for(int i =0; i < IN_DATA_SIZE; ++i) {
         data[i] = pIn[i];
    }

    // 将nonce写入block header数据内
    uint32_t nonce = puId + nonceOffset;
    memcpy(data + NONCE_OFFSET, &nonce, 4);

    // 第一次计算hash(128byte)
    memset(hashResult, 0, 64);
    DoHash(_s, data, 2, hashResult);

    // 第二次hash前的补位(64byte)
    hashResult[32] = 0x80; // sha256补位分隔符号
    uint8_t rawDataSize[8];
    WriteBE64_EX(rawDataSize, 32 << 3); // 写入big endian (<<3的是乘以8)
    memcpy(hashResult + 56, rawDataSize, 8);

    // 第二次计算hash
    DoHash(_s, hashResult, 1, hashResult);

    // 将本workitem的双hash结果拷贝到输出buf中
    uint64_t outDataOffset = puId * OUT_DATA_SIZE;
    #pragma unroll
    for(int i =0; i < OUT_DATA_SIZE; ++i) {
        pOut[i + outDataOffset] = hashResult[i];
    }
}